This research program is concerned with the etiology, pathogenesis, prevention, early detection and treatment of the Respiratory Distress Syndrome in infancy. We propose to develop predictive indices with the aid of a computer to identify the fetus or infant at highest risk of developing hyaline membrane disease, and in particular, those infants who are likely to die or require prolonged and complicated therapy. New methods of monitoring the fetus are being explored, viz. fetal breathing and continuous recording of PO2 by transcutaneous techniques. The biochemical development of the lung, the distribution of water in the lung as well as the influence of vasoactive polypeptides are being studied and the influence of asphyxial insults of these determined. The intracellular pH during acute hypercapnia is being studied experimentally to determine the in vivo buffering capacity. New methods of controlling serious bacterial infection through the implantation of normal bacterial flora as a host defense mechanism is being explored and a detailed metabolic evaluation of various nutritional regimens currently in use or proposed for the near future is being undertaken.